1. Field of the Invention
The invention relates to a system for producing semiconductor layer structures by way of epitaxial growth.
2. Discussion of the Prior Art
It is known to deposit a monocrystalline semiconductor layer, e.g., of GaAs and related III-V compounds onto semiconductor wafers by way of epitaxial growth. According to the organometallic chemical vapor deposition (MOCVD technique, the semiconductor wafer to be coated is heated up to the required reaction temperature and is exposed to a gas flow which contains the coating substance in the form of a gaseous organometallic compound and deposits it on to the semiconductor wafer (cf. J. Vac. Sci. Technol., 18(3), April 1981, pp 753 to 755; J. of Crystal Growth 64 (1963), pp 461 to 470).
The conventional systems comprise a reactor accessible from one side into which the semiconductor wafer to be coated is introduced upon opening the reactor. Thereupon, the reactor is closed and, if so required, filled with an inert gas, the semiconductor wafer is heated up to the required reaction temperature and is then exposed to the reaction gas flow. Each time that finished semiconductor wafers are to be removed from the reactor and new wafers are to be introduced, the reactor has to be cooled down to the ambient temperature, and opened. In so doing, ambient air also enters into the reactor so that thereupon the latter must be carefully deaerated. This results in idle time for the system which is long compared to the time of treatment. This also results in heat-energy losses because the reactor must be reheated each time.